Nailing slot structure for panel



March 223, J. A. BERRaDsrE, 3,399,82Q

MAILING SLOT STRUCTURE FOR PANEL Filed July 14, 1964 2. Sheets-Sheet l I f L gzz INVENTOR, JACK A. BERRIDGE ATTORNEY March 2;, i967 NAILING SLOT STRUCTURE F Filed July 14, 1964 I J A. BERRIDGE OR PANEL 2 Sheets-Sheet 2 INVENTOR. JACK A. BERRIDGE BY M 5% ATTORNEY United States Patent Ofifice 3,309,829 Patented Mar. 21, 1967 3,399,829 NAILING SLOT STRUCTURE FOR PANEL Jack A. Ber-ridge, Alameda, Califi, assignor to Kaiser Aluminum & Chemical Corporation, ()akland, (Salli, a corporation of Delaware Filed July 14, 1964, Ser. No. 382,480 7 Claims. (Cl. 52-506) This invention relates to roofing or siding structures in which sheet metal panels of considerable length are employed.

Sheet metal panels, and particularly panels composed of aluminum and alloys of aluminum, have many recognized advantages over other roofing and siding materials, but they also present special problems, chiefly because of their high coeflicients of thermal expansion relative to the underlying sheathing.

When panels of substantial length are used, the mere driving of rooting nails through the panels and into the roof deck at spaced points is unsatisfactory, because the connection is unyielding. With falling temperature the panel material is strained and incipient tears may be started at the nail holes, while with rising temperature the panel may be caused to buckle between the points of attachment.

One expedient which has been proposed for overcoming this difficulty has been to provide each panel with a plurality of aligned nailing slots, all of a uniform width exceeding the shank diameter of the conventional roofing nail employed.

While this may partially avoid buckling and overstraining of the panel metal by the nails, it still presents difiiculties. Since there is nothing to guide the workman as to the correct location of a nail relative to the slot, the nails may be driven more or less at random, and certainly not within a prescribed, narrow limit of variation. Some of the nails, at least, may eventually engage the slot ends, one after another, and each, in turn, will be subjected to excessive strain. The nails become permanently distorted or loosened, and they cause the very damage to the panels which the slots were intended to avoid.

Then too, there is no lateral play which may be productive of cracking and rattling.

It is a primary object of the invention to overcome these drawbacks through a novel structure which is adapted quietly and efi'iciently to accommodate relative expansion and contraction without excessive strain or buckling of the panel material, but which leaves little or no capacity for unrestrained lost motion between the panels and the attaching nails. Most desirably, the composite structure utilizes the elasticity of the panel material, within the elastic limits thereof, constantly to oppose relative movement of the panel and the nails, and yieldingly to urge all displaced portions of the panel to return toward their original, datum positions.

To this end, it is a primary feature of the invention that aligned nailing slots are provided, each having an enlargement at the middle thereof, for visually and physically guiding the workman in the placement and driving of each nail.

Most advantageously, each slot is made to have a uniform, given width slightly less than the shank diameter of a specified roofing nail, but with a central enlargement which is wider than the shank diameter of the nail, and which forms a visual and physical nailing guide. Under this practice the nail can be inserted freely only in the enlargement of the slot.

Other objects and advantages will hereinafter appear.

In the drawing forming part of this specification, practical and advantageous structures are shown which embody features of the invention.

FIGURE 1 is a fragmentary view in elevation, on a reduced scale, showing one conventional arrangement of metallic panels, wherein the present improvements may be advantageously employed;

FIGURE 2 is a fragmentary sectional view, taken in a plane at right angles to the roof deck, and showing an illustrative panel nailed to the roof deck, the plane of the section being indicated by the line 22 of FIGURE 1;

FIGURE 3 is a greatly enlarged fragmentary sectional view, taken on the line 33 of FIGURE 2;

FIGURE 4 is a fragmentary vertical sectional view taken on the line 44 of FIGURE 3;

FIGURE 5 is a View similar to FIGURE 3, but on a somewhat smaller scale, and showing a modified form of slot; and

FIGURE 6 is a view like FIGURE 3, but showing a modified form of nail.

A roof deck 10 is shown in FIGURE 1 of substantial pitch, but the pitch could be greatly increased or diminished, and the so-called deck could even be the sheathing or siding of a vertical wall, within the range of usefulness of the invention. The structure is shown as including a solid sheathing layer of boards or plywood. The boards 12 are covered first by a layer of asphalt saturated felt 14, and then by sheet metal roofing material 16. A wooden ridge strip 18 is provided along the top.

The roofing material includes a number of minor parts not essentially relevant to the present invention, but it consists shiefly of panels 20 (FIGURE 2) with which the instant invention is directly concerned, Each panel 23 consists of sheet aluminum, or other appropriate sheet metal, which is pre-forrned to provide two upstanding hollow nailing ribs 22 of substantial width and height. As shown in FIG. 2, one nailing rib 22 is provided at the left hand margin of the panel, and the other about midway of the width of the panel. At its right hand boundary the panel is provided with an upstanding hook portion 23 which is adapted to fit and lock within the first nailing rib of the next panel. In the finished roof the nailing ribs areuniformly spaced from one another. Each panel is flattened at its upper end, is wrapped part-way around the ridge strip 18, and is fixedly secured to the ridge strip. From the ridge strip, the panel extends continuously downward to the cave. According to present commercial practice, each panel has an effective coverage of thirtytwo inches of width, exclusive of overlap.

Aligned nailing slots 24 are provided at uniform intervals along the uppermost wall 26 of each rib, being desirably spaced, say, on eight inch centers. The wall 26 extends in a plane parallel to the sheathing of the deck, and in the structure shown its upper surface stands fiveeights inch out from the roof deck. It is to be understood that each roofing panel 20 with the plurality of the slots 24, two of which are indicated in FIG. 1, of the instant invention is merely for the purpose of illustration in FIGS. 1-2.

Moreover, details of the slot 24 and of the associated nail 28 are illustrated on a greatly enlarged scale in FIGS. 3-4. The slot 24 is made long enough so that the shank 30 of a nail initially located at the center of the slot, or within a prescribed distance of the center, will never be caused to engaged a slot end, even in the slot which is farthest from the anchored end of the panel. The slot has a uniform, given width, being bounded by parallel, longitudinally extending edges 32 and 34. The given width of the slot is exceeded slightly by the shank diameter of the conventional roofing or siding nail 28 so that the nail shank cannot be freely inserted in the slot portions of given width. Midway of the length of the slot, recesses 35 provide an enlargement in which the nail shank can be freely inserted. Since the recesses 36 may be regarded as the end portions of a crossing, secondary slot, the entire slotted area may be accurately described as in the nature of a cruciform. The slot is longitudinally symmetrical and transversely symmetrical in construction. The cruciform slot has four reentrant angles formed by metallic corners 38 of the panel material, and it is the spacing of diagonally opposite corners 38 which limits the size of the nail shank that can be freely accepted in the enlargement of the slot.

It is not essential that the nail shank be large enough to contact the four corners 38 simultaneously, since contact with a pair of the corners will satisfy the requirement for centering with a practical degree of precision. A limited departure from precise centering can be accommodated by selection of an appropriate length for the slot ends of given width. Tests have shown that the over-all change of length of a panel twenty feet long, relative to the roof deck, caused by thermal expansion and contraction, under extremes of outdoor temperature, is only one-quarter inch.

A change of initial or datum conditions caused by rise or fall of temperature does not produce, nor tend to produce, a uniform overall creeping of the panel, but a displacement does result which varies with temperature and with distance from the point of positive anchorage of the panel.

The depth of penetration of a nail into the ends of the associated slot 24 will be different for differently located nails, depending on the distance of the particular nail from the area of positive anchorage.

With the construction illustrated, the nail shank cannot enter either slot portion of given width without displacing and putting under strain a small amount of the metal which borders the slot. It is important that the amount of metal involved be so slight, and the distortion so limited, that the metal is never strained beyond its elastic limit. Each slot end, however, resists entry of the nail shank with a light, resilient force, and opposes progression of the nail shank along the slot. By choosing a shank diameter which exceeds the slot width by a very small amount, the resistance to relative movement can be made as small as desired. With proper selection a nail, which has been driven deep into a slot end by construction of the panel, cannot become bound against withdrawal when the panel reexpands. Both edges 32 and 34 are constantly engaged by the nail shank, however, so that there is no lateral lost motion, and no alternate making and breaking of metallic contact between the nails and the slot walls can occur. Objectionable noises, therefore, are largely avoided.

The invention is not limited to the employment of panels which run in the direction from ridge to cave. It is also applicable to siding panels, and to roofing panels which are designed to run, and do run, parallel to the ridge strip. In either of the latter cases, the panel would be positively anchored, if at all, substantially midway of its length, and would undergo thermal expansion and contraction equally and oppositely from its center, thereby reducing the extreme relative movement of the nails at the panel ends by half.

The slot design also admits of substantial variation within the scope of the invention. FIGURE shows a structure in which the panel, itself, and the nailing slot-s run horizontally. In FIGURE 5, the nailing slot has been altered in several respects, as compared with FIG- URE 3. The secondary slot has been narrowed and considerably extended, the length of the primary slot has been substantially increased relative to the maximum thermal expansion and contraction encountered, and a nail is utilized whose shank simultaneously touches all four of the corners 38a. Since the slot structure of FIGURE 5 differs from that of FIGURE 3 only in the details just referred to, corresponding reference characters have been applied to corresponding parts with the subscript a added in each instance, and no general detailed description will be given. Some additional details will, however, be brought out in the following discussion and analysis.

Since the four corners 38a will just accept the shank 39a of the nail 28a, without deformation of the panel metal, they constitute both a visual and a physical guide to the workmen in placing and driving of a nail exactly at the middle of a cruciform slot. The nails positively preclude vertical movement of the horizontally extending panel. The panel cannot move horizontally relative to the sheathing without deformation of the panel material at and adjacent to the corners 38a. Because the panel metal is bendable and resilient, each nail acts yieldingly at the very outset to resist longitudinal movement relative to the sheathing of the panel area which it engages.

It is important that a nail shank not produce a strain of the panel material beyond the elastic limit of the metal, and that it not become bound in a slot portion of given width.

The slot 24a, when designed as shown, is well calculated to avoid these difiiculties. In the illustrated slot of FIG. 5, the radius 17 from a central point e to one of the corners 38a makes an angle of 22 /2 with the vertical center line :2 of the cross slot. Line e, drawn tangent to the periphery of the shank 33a at the end of radius d extends at right angles to b, and hence makes an angle 22 /2" with the longitudinal center line f of the main slot 24a. As the nail shank moves into the left hand end of the main slot, it operates upon the principle of the inclined plane to wedge a narrow marginal portion of the panel metal. Since the tangent of 22 /2" is equal to the square root of 2 minus 1, the ratio of nail shank travel to marginal metal displacement is the reciprocal of this figure or the square root of 2 plus 1. The nail shank, therefore, acts with a mechanical advantage of approximately 12 to 5. There is nothing of special importance about this particular mechanical advantage, nor is any mechanical advantage necessarily required, but the point is mentioned to bring out the fact that a variation in resistance to the relative movement of the nail shank 30a into slot 24a can be made available.

The length of the slot 24a and the depth of the notches 36a have an important bearing upon the characteristics of the resistance opposed to penetration of the nail shank into an end of slot 24a, and the avoidance of straining the panel material beyond its elastic limit. The deformation of panel metal is largely confined to the marginal area which lies between the slot edge 26, for example, and a line g drawn tangent to the end portions of the main slot and of the cross slot. This marginal area is relatively wide at the corners 3i) and the initial penetration is slight, so that the metal can be easily bent out of the way, but the farther the nail shank penetrates the slot 24a, the narrower the marginal area becomes between the nail shank and the line 3 so that the resistance is progressively increased. Only. a minor portion of the length of slot 24a is ever penetrated, yet the surplus length of the main slot 24a has an important bearing upon the magnitude of the resistance to penetration, and the rate of change of the resistance, because it affects the slope of the line g.

It is desirable that the marginal metal of all slots continually exert a force which not only resists penetration of the nail shank, but which actually seeks yieldingly to expel the nail shank from the penetrated slot end. That mode of operation is realized in the structure of FIGURE 5. There is never any binding of a nail shank in a penetrated slot.

One feature which helps to avoid binding is that the panel metal is largely held out of contact with the surface of the nail shank which lies within the angle of repose; i.e., within, say, eleven degrew of the line b. A limited amount of such contact can be tolerated, however, since substantial portions of the metal will still be acting to exert an expelling force.

In FIGURE 6 the panel 141) is desirably the same as panel 14 of FIGS. 1-4, and the slot 24b is also the same,

but a different type of nail is employed. The nail 34b is really a drive screw, having rolled steep pitched, multiple threads which start a short-distance below the head and continue down to the tip.

It is a well-known fact that the rolling of a screw thread produces an outside body diameter greater than that of the unmodified, cylindrical shank. The resulting nail or drive screw may be caused to have 'a lower, threaded body portion whose threads will just touch the four slot corners 38b, and reduced neck portion 42 whose diameter, as shown, is slightly less than the given width of the slot 24b. The reduced neck portion 42 might, however, be chosen to be exactly equal to the given width of the slot 24b, or slightly to exceed that width, as desired. When the nail has been driven, it is only the neck portion which lies in the plane of the slot walls.

Having now described the invention, what is claimed is:

1. An anchoring or covering structure comprising the combination with sheathing of an elastic sheet metal panel having a plurality of aligned nailing slots of generally uniform, given Width, each slot having an enlarged central portion of a greater width than the given width, and headed nails securing the panel to the sheathing, each nail having its shank driven through the enlarged central portion of one of the slots, and having a shank diameter small enough to be freely received only at the enlarged central portion of the associated slot, but of somewhat greater diameter than the given width of the slot.

2. An enclosing or covering structure, comprising the combination with sheathing of an elastic sheet metal panel having a line of lengthwise extending nailing slots of generally uniform, given widths, each slot having an enlarged central portion of a greater width than a given width, and headed nails securing the panel to the sheathing, each nail having its shank driven through the enlarged central portion of one of the slots, and having a shank diameter small enough to be received only at the enlarged central portion of the associated slot, but greater than the given width of the slot by an amount sufiicient to produce a light, stabilizing resistance to penetration of any slot portion of given width, but not sufiicient to produce a straining beyond the elastic limits of the margins of the slot portions of given width.

3. An enclosing or covering structure as set forth in claim 1 in which the opposite ends of the slot extend out from the middle substantially farther than would be required to accommodate maximum, normally induced penetration of the slot end by the nail shank, and the slot width, where enlarged, exceeds the given width of the slot by several times the amount that the nail shank diameter exceeds the given width of the slot.

4. An enclosing or covering structure comprising the combination with sheathing of an elastic sheet metal panel having a longitudinal series of aligned nailing slots of generally uniform given widths, each slot having an enlarged central portion of a greater width than the given width, and headed nails securing the panel to the sheathing, each nail being driven through the enlarged central portion of one of the slots and having a shank diameter small enough to be received within the enlarged central portion of the associated slot but somewhat greater than the width of the slot, but having a neck portion of restricted length, immediately beneath the nail head, of a diameter less than the nail shank diameter, and not substantially greater than the width of the slot.

5. A sheet metal panel for covering an underlying structure in combination with at least one roofing nail, said panel having a plurality of nailing slots of generally uniform given widths disposed therein, each slot having an enlarged central portion of a greater width than the normal width both of the slot and the adjacent shank portion of said roofing nail that is freely passed therethrough and into said underlying structure, the construction and arrangement of a given slot being such that the enlarged central portion of the given slot is adapted to serve as a visual and physical nailing guide for the reception and substantial centering of the nail relative to the slot, the centering of the nail within the enlarged central portion of the given slot enabling free thermal expansion or contraction of said panel relative to said underlying structure and the nail disposed therein.

6. A sheet metal panel for covering an underlying support structure in combination with at least one roofing nail and having a plurality of horizontally symmetrical and vertically symmetrical cruciform nailing slots, the panel metal bordering a portion of each slot forming four reentrant angles the vertices of which angles are quadrangularly related and said vertices receiving between them the cylindrical shank of said roofing nail which nail shank is of such large diameter that it is accepted in the slot without deformation of panel metal by being inserted in a slot area limited by said vertices.

7. A sheet metal panel as set forth in claim 6 wherein the shank of said roofing nail includes a reduced neck portion.

References Cited by the Examiner FRANK L. ABBOTT,

A. C. PERHAM, Assistant Examiner.

Primary Examiner. 

1. AN ANCHORING OR COVERING STRUCTURE COMPRISING THE COMBINATION WITH SHEATHING OF AN ELASTIC SHEET METAL PANEL HAVING A PLURALITY OF ALIGNED NAILING SLOTS OF GENERALLY UNIFORM, GIVEN WIDTH, EACH SLOT HAVING AN ENLARGED CENTRAL PORTION OF A GREATER WIDTH THAN THE GIVEN WIDTH, AND HEADED NAILS SECURING THE PANEL TO THE SHEATHING, EACH NAIL HAVING ITS SHANK DRIVEN THROUGH THE ENLARGED CENTRAL PORTION OF ONE OF THE SLOTS, AND HAVING A SHANK DIAMETER SMALL ENOUGH TO BE FREELY RECEIVED ONLY AT THE ENLARGED CENTRAL PORTION OF THE ASSOCIATED SLOT, BUT OF SOMEWHAT GREATER DIAMETER THAN THE GIVEN WIDTH OF THE SLOT. 